1. Field of the Invention
The present invention relates generally to electric switches, and particularly to electric switches that include mechanical actuators.
2. Technical Background
Electrical switches are used, of course, to control the state of electrical loads such as lighting elements, fans, and other such equipments. Electrical switch units are typically wall mounted in a location that is proximate the load. For example, light switches are usually located at the entry point of a room or a space so that a person entering the room can turn the lights ON before entering. Wall mounted electrical switches often include mechanical actuators such as toggle switch actuators, lever switch actuators, paddle switch actuators, push-button actuators and the like.
Based on consumer taste and convenience, there is a need for a push button actuated electrical switch. The push button switches currently on the market almost always include electronic switch actuators because of the in-out motion of a push switch lends itself to electronic push-button switch actuators rather than mechanical switch actuators. However, electronic switch actuators have drawbacks relative to mechanical switch actuators. They are more expensive, generate more thermal energy (heat), are larger, and are not as robust. What is needed, therefore, is a push button switch that includes a mechanical actuator to mitigate the aforementioned drawbacks.
In one approach that has been considered, a push button actuator is coupled to a rotatable block by a pressure-transmission gear. This approach has several drawbacks associated with it. The pressure-transmission gear is laterally unstable and the interface between the pressure-transmission gear and the rotatable block is prone to being jammed when the user applies downward pressure to the push button actuator. Another drawback to this approach relates to the tendency for contaminants to enter the mechanical switch space and fouling the switch contacts. What is needed, therefore, is a push button switch that includes a mechanical actuator that overcomes the aforementioned drawbacks.
Another issue that arises in various types of switching devices relates to the function and placement of indicator lights on the switching device itself. Some switches are known to include a pilot light that is illuminated when the switch is turned OFF. A load light is one that is illuminated when the switch is turned ON; this type of light provides the user with an indication that power is being delivered to the load. Another type of indicator is a “power-available light.” This indicator shows the user that power is available to the switch, and thus, is illuminated—when power is available—regardless of whether the switch is ON or OFF. One drawback associated with mechanical switch devices (that include indicator lights) relates to the fact that the switch actuator is movable. If the light indicator element within the switch moves with the switch actuator, then the light output is substantially uniform. On the other hand, the electrical wiring must move with the light element (to provide electricity); as a result, the wiring is continually being flexed. If, on the other hand, the light indicator element within the switch is stationary, the continual flexure of the electrical wiring is avoided while providing the mechanical switch actuator freedom of motion. The drawback with this solution is that the light output of a stationary light will be non-uniform. For one type of indicator light or another, the light output will be more effective in one actuator position than another. This issue becomes especially apparent for the power-available light or for universal light assemblies that can be wired by the installer to accomplish the various functions. What is needed, therefore, is an indicator arrangement (within the switch) that provides efficient and consistent light output regardless of actuator position.
Turning now to another consideration, there are several drawbacks associated with conventional installation methods and conventional protective electrical wiring devices. Conventional protective electrical wiring devices often do not make efficient use of space. In addition, mounting the wiring device's ground strap to the device box is tedious, time consuming, and therefore costly. The same can be said of mounting the cover plate to the electrical wiring device. Moreover, in multi-gang installations, the finished look is often ragged because the plurality of electrical devices and their respective cover plates are typically not in alignment. This misalignment can be, and very often is, in all three dimensions. Retrofitting an electrical installation can also be problematic from the standpoint of the finished look because the device box, or an old work box, may not be precisely aligned to the plane of the wall surface. This is especially true if the wall surface itself is uneven. After remodeling a space, homeowners often seek to replace an existing wall plate with one that better matches the new décor. Thus, a homeowner may inadvisably remove the faceplate cover from an energized wiring device and inadvertently become exposed to a shock hazard from the “hot” electrical wiring.
What is needed therefore is a switch that addresses the drawbacks articulated above. A switch of this type is also needed that can be employed in a number of different form factors including one suitable for use in a modular framing system such that it does not require fasteners to be securely installed within the device box.